The invention relates to an arrangement for measuring the distance of two oppositely arranged roller ways of a continuous casting plant, comprising a measuring body capable of being pulled or pushed through the section between the roller ways, which measuring body includes oppositely arranged contact surfaces touching the surface areas of the rollers, and a distance-measuring device fastened within the measuring body.
An arrangement of this kind is known from U.S. Pat. No. 3,983,631. The measuring body of this known arrangement is made of an elastomeric material, such as rubber or plastics, and the distance-measuring device is embedded within this body. This arrangement has proved successful in continuous casting plants, however with the prerequisite that, for obtaining a faultless measured result, the rollers of the roller ways lie directly opposite each other. If the rollers of the roller ways are arranged in an offset manner, which means that not every roller of one roller way has a roller of the other roller way arranged exactly opposite, but that a roller of one roller way--viewed in the longitudinal direction of the roller ways--lies between two rollers of the other roller way, the distance of the roller ways can no longer be accurately measured with this arrangement. The body, which is made of an elastomeric material, in such a case avoids the one roller and is pressed too much in between the two rollers of the opposite roller way.
It is furthermore known from German Offenlegungsschrift No. 25 38 141 to equip an arrangement for measuring the roller distance with a casing from whose wall sliding rockers resiliently pressed outwardly stand off on one side, which rockers get into contact with two neighbouring rollers of one roller way. The casing itself rests on two rollers of the oppositely arranged roller way via sliding rockers rigidly mounted to it on the opposite side. Beside the rockers, distance-measuring devices are provided which get into contact with the surface areas of the rollers of one roller way by means of tracing heads. The rigidly designed sliding rockers, during each measuring process, form a tangent common to all of the rollers. Also with this arrangement, a faultless measured result is not possible unless the rollers of the two roller ways are arranged directly opposite each other, since this arrangement does not measure the distance of two rollers in the radial direction, seen from the center of curvature of the bending line of the strand, but the normal distance of the surface of an inner roller to the common tangent of two neighbouring outer rollers. Difficulties will arise in particular in the region of the arc of a strand guide, as well as in those roller way regions which show uneven conditions of curvature, such as the bending and straightening zones. Furthermore, difficulties will arise also in case the rollers are not evenly distributed over the total length of the roller ways. This is always the case in modern fast continuous casting plants, since at the beginning of the roller ways--immediately below the mould--rollers having very small diameters are arranged closely adjacent, whereas towards the end of the roller way the roller diameter--due to the solidification of the strand--may be chosen to be larger, which results in a greater roller division.